By Michael Hernandez

WASHINGTON 

The U.S. scrambled jets to protect coalition forces who were assisting Kurdish forces in al-Hasakah, Syria, after they came under attack by Syrian warplanes, the Pentagon confirmed Friday.

No coalition forces were harmed in Thursday’s Syrian airstrikes, Pentagon spokesman Maj. Adrian Rankine-Galloway said.

Russia told the planes were not Russian via a U.S.-Russian de-confliction channel, according to Rankine-Galloway.

The “MOU [Memorandum of Understanding] channel” was established to ensure air safety between the U.S. and Russia shortly after Moscow began an independent air campaign in Syria last September.

“We made clear that coalition aircraft would defend its troops on the ground if threatened,” he said. “The Syrian regime would be well advised not to interfere with coalition forces or its partners.”

Syrian warplanes on Thursday struck YPG-held parts of al-Hasakah, killing five civilians and a YPG militant in the city’s Salihiya, Tel Hajer and al-Mufti districts, according to local sources who spoke to Anadolu Agency on condition of anonymity due to fears for their safety.

YPG forces responded by shelling Syrian Army positions in the city’s central district, the same sources said.

When asked if coalition forces were assisting the YPG in al-Hasakah, a U.S. official who spoke on condition of anonymity because he was not authorized to discuss the matter publicly, said that assistance was being given to the Syrian Democratic Forces.

The U.S.-backed group is a coalition of fighters that includes the YPG, and other Kurdish groups, as well as Arab and Turkmen militias. 

Turkey considers PYD and its military wing YPG to be terrorist groups, and affiliates of the PKK separatist terrorist organization.

Since the Syrian conflict began more than five years ago, fighting has sporadically erupted between Syrian forces and the YPG in northern Aleppo’s Sheikh Maqsoud district and at checkpoints and oilfields near al-Hasakah.